The downing of the Malaysian airlines flight MH17 last week, allegedly by pro-Moscow rebels using Russian arms, has changed the European position and "require a much tougher response," said Britain Foreign Minister Philip Hammond.
"It is time for an arms embargo, time to wake up a bit", said Lithuanian Foreign Minister Linas Linkevicius. "We are talking about a terrorist act."
"We cannot go on doing business as usual with a country when it's behaving in this way", said British Prime Minister David Cameron in a statement to parliament, as he pushed the EU to enter its "Phase 3" sanctions, which target economic sectors and cause much more pain for all sides.
This situation has divided Paris and London, as François Hollande said the agreement to supply Russia with two Mistral warships is still in place - but Hollande added the delivery of the second Mistral ship would "depend on Russia's attitude."
But this gap is not only felt on both sides of the Channel.
Most of the poorest European countries rely on strong Russian economic ties, mainly for energy and could be badly affected by economic sanctions.
Germany, often criticised for being slow to act, conceded that something has to be done after the downing of the Malaysian airline but favours dialogue.
"We remain ready to help with political and diplomatic means to help de-escalate the situation", said Germain Foreign Minister Frank-Walter Steinmeier.
The severity of the European response will mainly depend on the Netherlands, which suffered the most important losses in the Malaysian MH17 crash.